What’s the next big thing?
That’s a question often posed to the ag community. The answers evolve as new crops, practices and equipment take their place either on the pedestal of innovation or the scrapheap of history.
Herbicide resistance, environmental concerns and the growth of organic farming have necessitated ways to kill weeds without the use of chemicals. Several machines that could at least reduce dependence on herbicides have been invented.
It’s a technology that has the potential to be much more than a passing fad.
“I would be very surprised if it didn’t go somewhere,” said University of Illinois weed scientist Adam Davis.
The Harrington Seed Destructor, introduced in Australia a few years ago, is a machine either pulled behind or attached to a combine. The idea is to destroy weed seeds that are ejected as chaff during harvest. The University of Illinois is one of several research centers that have tested the machine.
So far, it has proven to be up to the task.
“When (the seeds) hit the ground they’re not going to survive winter,” Davis said. “The percent destructed has been in the high 90s. They seem to be quite reliable in terms of service and installation.”
Implements with other modes of action have also been introduced. Among them is the Weed Zapper, a machine that uses static electricity to destroy weeds sticking above the crop canopy. Introduced in 2019 by Old School Manufacturing in Sedalia, Missouri, the device is finding customers.
About 17 or 18 of the units were sold in the first year, said Old School’s Nicole Kroeger. Today there are more than 300 in the field. The Zapper is a tractor implement that carries a generator and transformer that shoots 15,000 volts of electricity to the front bar.
“Our target is to hit the weeds that are above the crop canopy,” Kroeger said. “Ideally, these would be used in soybean fields or pumpkin patches.”
Davis has also tested the Weed Zapper. Its effectiveness is demonstrated in a visual manner.
“It’s pretty dramatic if you do it at night,” he said. “It lights up like a flare.”
While such a machine would suit organic operations where herbicides are forbidden, Kroeger said usage is about 50% conventional. Still, organic farming obviously benefits from such technology.
“In row crops like corn and soybeans, they are coming up with new technology. Automated robots going down the row and taking out the weeds,” said Dave Chapman of the Real Organic Project. “They’re like vacuum cleaners that vacuum your house while you’re away. I have seen ones like a finger weeder with little tines that go through the field. It’s not quite there yet. It’s still being developed in the trial stage.”
Other companies have entered the mechanical weed control market. The U of I’s Girish Chowdhary led a team that tested the TerraSentia robot manufactured by Earth Sense. In addition, a Boston- area company produces the Tertill, a small, solar-powered robot similar in appearance to the Roomba vacuum. It is designed to weed garden-size areas.
Davis is impressed with the Weed Zapper, though it does have an obvious drawback.
“Clearly that’s problematic because you lose a lot of your yield before those weeds have emerged above the crop canopy,” he said. “But if you think about minimizing weed seed return, both giant ragweed and common waterhemp hold onto their seeds until mid to late September, so you have a chance to get them above mature crops and canopy before you harvest and before those seeds have matured.”